1. Field of the Invention.
This invention relates to a multiport, diaphragm-sealed valve mechanism. In one of its aspects it relates to a motor-actuated, multi-position, sampling valve suitable for use with general process and analytical systems. In a more specific aspect of the invention it relates to a multiport valve with a uniform action mechanism for simultaneously sealing all transfer passages as the channels of flow are repositioned. In another of its aspects it relates to a method for transferring fluid samples and purge fluids through analyzer systems. In yet another of its aspects it relates to a method for manipulating the transfer of multiple fluids through a multiport valve mechanism with leakage and intermingling of transfer fluids minimized to the point of elimination.
2. Description of the Present State of the Field of the Invention
In a series of prior United States patents of which A. B. Broerman is an inventor--U.S. Pat. No. 3,111,849, 3,198,018, 3,140,615, 3,376,894, 3,387,496, 3,492,873, 3,545,491, 3,533,426 and 4,276,907--all incorporated herein by reference, various apparatuses have been set forth relating to multiport valve mechanisms particularly for use with chromatographic analyzers. In this series of patents the use of fluid piston operation to activate the valves is explored along with various means for sealing the fluid transfer pathways within the valve. In general, the actuation of the valves used in current practice depends on the use of individual electrical signals to switch individual solenoids to air power to actuate individual valve operators thereby causing use of a complex and, therefore, expensive multiplicity of solenoids in the valve operation and also provides an increased opportunity for fluid leaks and intermingling of transfer fluids. None of the prior art sets forth apparatus incorporating instantly actuated operation of the valves and uniform action, positive, simultaneous sealing of the flow paths as the paths are switched from one to another.
It is therefore an object of this invention to provide a rotary valve apparatus and method of operation that instantly switches the paths of flow within the valve. It is another object of this invention to provide valve apparatus and method of operation that simultaneously produces a positive seal of all the fluid pathways within the valve as the flow in the pathways is switched from one to another. It is another object of the invention to provide a sampling and column switching valve for use with analytical and other process systems which minimizes leaks and intermingling of fluids to the point of elimination. Still another object of the invention is to provide a valve for use with analytical systems which combines the functions of sampling and column switching in a single unit which is electrically actuated instantaneously and operates without leakage or intermingling of the transfer fluids. A specific object is to provide a valve with a twelve port configuration according to this invention.
These and other aspects and objects of the invention will become apparent on studying the following specification and claims along with the appended drawings.
SUMMARY OF THE INVENTION
According to this invention there is provided a multiport valve which has (A) a plunger body having a first, flat face and a second, flat face, (B) a detent plate; (C) a flat surface abutting the first, flat face of the plunger body and (D) at least one diaphragm inserted between the first, flat face of the plunger body and the surface abutting the first, flat face of the plunger body covering the area therebetween. The first, flat face of the plunger body has at least one, circular groove with the at least one groove pierced at equidistant intervals by a multiplicity of plunger passages with each, plunger passage (a) passing through the plunger body to the opposing, second, flat face, (b) retaining therein a plunger and (c) retaining partially therein a spherical body. The surface abutting the grooved, first, flat face of the plunger body includes transport tubing openings aligned at intervals in at least one, circular pattern concentric with and having the same diameter as an at least one, circular groove of the plunger body and with openings aligned between the plunger passages of the plunger body. The detent plate (a) has a flat face having indentions therein aligned at intervals in at least one, circular pattern concentric with and having the same diameter as the at least one, circular groove; (b) is held in position with the flat face of the detent plate facing the second, flat face of the plunger body so that the flat face of the detent plate holds each spherical body in sufficient, rollable tension in a retaining, plunger passage against a plunger to seal the diaphragm at the opposing end of the plunger against the surface abutting the grooved, first, flat face of the plunger body; and (c) is rotatable around an axis designated by a line joining the centers of the circles described by the at least one, circular groove and the at least one, circular pattern of indentations so that on partial rotation of the detent plate the spherical bodies providing tension on a portion of the plungers in the same groove simultaneously come to rest in indentations thereby allowing relaxation of the sealing of the diaphragm by these plungers against the abutting surface.
Also, according to this invention, there is provided a method for operating a multiport valve of this invention to provide combined sampling and column switching for operation of analytical and other processes by directing flow through specific paths for automatically-controlled periods of time.
In a specific embodiment, used to illustrate this invention, there is provided, with method of operation, a multiport valve which has twelve, transport tubing openings in equal spacing in two, concentric, circular patterns each having six openings aligned with the two grooves on the first face of the plunger body and with each groove providing entrance to six, equally-spaced, plunger passages. The detent plate has two, concentric, circular patterns of three indentations spaced at 120.degree. intervals aligned with the concentric grooves on the plunger body. The detent plate is rotated in 60.degree. movements which during the period in which none of the spherical bodies are aligned with the indentations in the detent plate causes sealing of all of the passages between transport tubing openings. On alignment of a spherical body with an indentation in the detent plate, the seal corresponding to that position is relaxed so that a path can be formed for fluid issuing from one of the transport tubing openings through the groove to the adjacent transport tubing opening.